Point Scale Equations
Take care in reading the literature: While position calculations require high precision, point scale does not.
- Leads to use of spherical ORS
- Erroneous conclusion that point scale is independent of longitude this is certainly not true for ellipsoids of revolution.
For UTM, a constant scale factor of 0.9996 (cscale) is used along the central meridian to reduce distortion
Error ? due to point scale distortion of meters per kilometer is , where k is the point scale and is the un-distorted true distance
- The linear error in a kilometer is then 1000 *?.
- For 10 kilometers, the error becomes 10000 * ?.
Adjudication of distortion errors is application dependent